Prisons in the first decade of the twenty-first century face both a wide range of age-old challenges as well as newly emerging ones. Five major developments of the decade have significantly influenced prison operations and introduced important changes in both day-to-day and ongoing institutional management. Two developments arise from internal changes—increasing populations and an ever-growing emphasis on security. The Prison Rape Elimination Act (PREA) represents an externally imposed development. New security/management technologies represent both a challenge and an opportunity for corrections. Finally, the increasing costs of corrections, arising from both internal and societal forces, are a major challenge for prisons.